Content last reviewed:
Information Sources
- primary literature - original material
- journal articles
- theses
- conference proceedings
- secondary - interpretations and evaluations that are derived from or refer to primary sources
- review articles
- books
- practice guidelines
- tertiary - distillation and collection of primary and secondary sources
- encyclopedias
- textbooks
- grey literature
- policies
- reports
- popular literature
- news
- blogs
- non-textual information
- data and statistics
- images
- GIS - geographic information system
Search Process
Searching the literature is an iterative process.
- Write your topic out as a sentence or question
- Identify the main ideas (concepts)
- Think of synonyms/related terms for each concept (search terms)
- Combine the search terms
- Select the database(s) you want to search
- Execute search
- Evaluate the results you find and revise your search strategy as necessary (and possibly your thesis)
- Repeat
Controlled Vocabulary
- List of preselected terms used to describe the concepts in an article/book - one term for:
- Synonyms or related terms
- Singular or plural
- Different spellings
- Referred to as:
- Thesaurus - lists words in groups of synonyms and related concepts
- Example:
MeSH (medical subject headings) for Medline
- Example:
- Subject Headings
- Example:
OMNI
- Example:
- Thesaurus - lists words in groups of synonyms and related concepts
- Helps you find relevant information
Keywords
- Use natural language to find information
- For a search to be comprehensive, need to consider all possible ways of expressing your idea
- Examples:
cancer(s), tumour(s), tumor(s), neoplasm(s)
Database Search Techniques
There are various ways to build a search strategy. Click on the links below to move to the relevant section.
Boolean Operators
To combine search terms we use AND/OR/NOT, referred to as Boolean operators.
AND
Image:
To find articles which contain all of your concepts:
- Combine them with AND
- Using AND narrows your search. The more words you combine with AND,the fewer results you will find.
- Examples:
allergens AND asthma AND children
OR
Image:
To find articles which contain any of your synoyms:
- Combine them with OR
- Using OR expands your search. The more words you combine with OR, the larger the number of results you will find.
- Examples:
acute OR chronic OR bronchial
NOT
To eliminate non-relevant results:
- Combine with NOT
- Using NOT reduces the number of results you find. Use with caution as you may inadvertently remove results of interest
- Examples:
enzyme NOT signalling
Brackets
Use brackets to isolate your concepts and gather together your synonyms
- (acute OR chronic OR bronchial) AND (asthma)
Truncation
Truncation, also called stemming, is a technique that broadens your search to include various word endings.
- both the singular and plural forms of a word
- words that begin with the same word stem
- Truncation symbols vary by database; common symbols include: *, ?, #, $
- Examples:
child* = child, childs, children, childrens, childhood
genetic* = genetic, genetics, genetically
Wildcards
Wildcards broaden your search to include words with different spellings.
- This is useful if a word is spelled in different ways, but still has the same meaning.
- Wildcard symbols vary by database; common symbols include: #, ?
- Examples:
wom#n = woman, women
colo?r = color, colour
Proximity Operators
Proximity operators allow you to indicate how closely two search terms are positioned to each other. Words that are close to each other are more likely to be relevant than words that are widely separated.
- Using proximity operators will limit your search, resulting in a smaller set of results.
- A proximity operator has two components:
- letters which indicate a specific search syntax
- a number that indicates how close the words must be to each other
- Proximity operators vary by database; common symbols include: N5, W3, NEAR/4, adj2
- Examples:
allergies N5 asthma (to find the words allergies and asthma within 5 words of each other)
allergies NEAR/5 asthma
Phrase Searching
To find an exact phrase use quotation marks.
- Examples:
"chronic disease"
Formulating the question
- Write your topic out as a sentence or question
- Identify the main ideas (concepts)
- Think of synonyms for each concept
Researchers in health sciences often use a framework to help develop their question.
- PICO(S) - used mainly for quantitative questions
- Population or Patient
- Intervention or Issue
- Comparison
- Outcome
- Study Design
- SPICE - used for qualitative questions
- Setting
- Perspective
- Intervention
- Comparison
- Evaluation
Other mneumonics to help frame a question include:
- SPIDER - qualitative evidence synthesis
- Sample
- Phenomenon of Interest
- Design
- Evaluation
- Research Type
- ECLIPSE - policy/management questions
- Expectations
- Client group
- Location
- Impact
- Professionals involved
- Service
- Evaluation
- PS - qualitative questions
- Population
- Situation
Click on the link below to download a search strategy worksheet
Document:
Search Strategy Worksheet v1.xlsx
(12.4 KB)
Example
Question: Does e-cigarette advertising increase smoking up-take in youth?
PICO Framework with Search Terms
PICO Framework with Search Strategy
PICO Practice Examples
Identify the main concepts (PICOs) in each of the questions. Think of synonyms. Create a search strategy.
- Do fall prevention programs help prevent seniors from falling?
- What is the impact of infant nutrient intake on cognitive outcomes?
- How do social support and communication impact long-term care?
There are various search tools (databases) available. Click on the links below to move to the relevant section.
Library Search
You can use the Library Search to find what the library has in a particular subject area.
- For help using the Library Search see the Omni Search page.
Cochrane Library
The Cochrane Library (named after Archie Cochrane) is a collection of databases that contain different types of high-quality, independent evidence to inform healthcare decision-making. It is provided by the Cochrane Collaboration and other organizations. It includes the following databases:
Cochrane Systematic Reviews are considered the "gold standard" for systematic reviews and are at the top of the pyramid of best evidence for evidence-based healthcare.
Carleton does not have a subscription to the Cochrane Library however the search function of the library is freely available. Searching the library will help identify relevant information that you can then find in other databases or order through an interlibrary loan.
PubMed
PubMed is a free search engine accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics. The United States National Library of Medicine (NLM) at the National Institutes of Health maintains the database
PubMed Features
Go to the PubMed help guide.
Other Databases
Other Health related Databases
Other subject areas to consider that look at health from the perspecitve of their own discipline.
- Economics
- Education
- Environmental Science
- Nursing
- Philosophy
- Public Policy
- Psychology
- Social Work
- Sociology
- Technology
Grey Literature
Grey literature is an important source of information in the health sciences.
Grey literature is defined as "information produced on all levels of government, academics, business and industry in electronic and print formats not controlled by commercial publishing" ie. where publishing is not the primary activity of the producing body." — ICGL Luxembourg definition, 1997. Expanded in New York, 2004
Types of Grey Literature
- Government Information (open relevant accordian)
- Dissertations and Theses
- Conference Proceedings (select Conference Proceedings Citation Index- Science, you may also want to select the Social Science and Humanities option)
- Newspapers and Magazines
- Clinical Trials
- Clinical Practice Guidelines (also check Canadian Health Professional Association websites: CMA, RNAO, CPA, etc)
- Think Tanks
Resources
- Canadian Public Documents Collection (includes publications from Canadian research institutes, government agencies and university centres)
- Canadian Research Index (Provides detailed citations to monographs and serial publications in the Microlog microfiche collection located in MADGIC)
- eLibrary: Conference Board of Canada - Conference Board of Canada
- CADTH ( Canadian Agency for Drugs and Technologies in Health)
- Grey Literature Report (searchable bimonthly publication of The New York Academy of Medicine (NYAM))
-
Canadian Research Institutes and Foundations/Eastern Ontario Health Research Institutes (two different search engines
How-to Guide
- Grey Literature (UofT)
Search Tool worksheet
Citation Tracking
Citation tracking is an important aspect of the research process. You find a relevant article(s) and now you want to look at the sources cited by this article(s).
There are three databases that allow you to easily do this: Web of Science, Scopus and Google Scholar.
Web of Science
Web of Science can be used to easily find and access the references in an article as well as citing articles .
- Enter the title of your article of interest
- On the dropdown menu on the right, select Title
- Click Search
- Click on the title of the article in the results list
- Scroll down to the section entitled Other Information
- Click on the number of Cited References to see the list of references for this article
- Times cited refers to those paper who have cited this paper
Caveat: Not all references may be linked which means you may have to copy/paste the reference title into another database.
Scopus
Scopus can also be used to track references and papers citing an article.
- Enter the title of your article of interest
- On the dropdown menu on the right, select Title
- Click the magnifying glass icon
- Click on the title of the article in the results list
- Scroll down to see the references for this paper
- In the upper right hand corner there is a section Cited by... which will show the number of articles that have cited this article
Caveat: Scopus has more current content than Web of Science but less before 1996. You may have to copy/paste titles into another database if they are not linked.
Google Scholar
Google Scholar can also be used to track papers citing an article.
- Enter the title of your article of interest
- Find it in the list of results
- Look for Cited by XXX under the article title
Caveat: Not all of the citing article may be in Google Scholar.
Tracking your Searches
It is important to record the steps you take in your research process. This ensures that your results are reproducible. It will also make it easier to remember what happened at each step of the process when you come to write your paper/report.
You can easily record your search strategies in an excel spreadsheet. Make sure to include:
- Database name
- Search terms (strategy)
- Date of search
- Limits/Filters used
- Number of results
- Number of results after you remove duplicates
- Relevant results
For grey literature you will also need to record
- URL of the website
There may be other items you wish to record. Sometimes it is good to have a Comments/Notes section.
- Sample excel spreadsheet
- The University of Texas School of Public Health provides a detailed Excel workbook for tracking search strategies and results and to screen titles/abstracts called PIECES for systematic reviews.
NVIVO
- NVivo is a software package that helps with qualitative data analysis. Keep track of all data associated with your project, code your data, create models to help organize your research, run queries on your coded data, create charts and reports for sharing with others...
Keeping Current
- Email alerts:
- Table of contents
- database searches
- eg/ myNCBI saved searches
